xe2x80x98Co-op 25xe2x80x99 is a new and distinct cultivar of apple tree (Malusxc3x97domestica Borkh.), that was produced from crossing the selection PCFW 2-134 (unpatented) as the seed parent with the selection PRI 669-205 (unpatented) as the pollen parent in 1971 at the New Jersey Agricultural Experiment Station, Rutgers: The State University of New Jersey. The tree is a seedling of known parentage planted in May 1973 at the Clark Farm in West Lafayette, Ind. in the L Block, Row 20, Tree 41, hence its informal designation as CLR20T41. The seedling was selected as promising in 1978 and carried the progeny designation PRI 2714-4 in our breeding records. It was released for testing as Co-op 25 in 1984 and described in Purdue University Station Bulletin 456 (1984). FIG. 2 is a chart showing the complete pedigree of Co-op 25. This new cultivar is currently being sold under the trademark xe2x80x9cSCARLET O""HARAxe2x80x9d.
This new cultivar carries the genetic factor Vf inherited from Malus floribunda Sieb 821 that renders it highly resistant to the apple scab disease incited by Venturia inaequalis.(Cke.) Wint. Scab resistance was evaluated by controlled greenhouse inoculation tests at the seedling stage followed by twenty (20) years of observation under natural conditions for infection in the field in West Lafayette, Ind. and at multiple testing sites in the United States and abroad including sites in Italy, France, and Australia. Based on field observations, the selection is moderately susceptible to cedar apple rust incited by Gymnosporanium juniperi-virginianae (Schw.) and is moderately susceptible to mildew incited by Podosphaera leucotricha (Ell. and Ev.) Salm., and highly susceptible to fireblight incited by Erwinia amylovora (Burr.) Winslow, as well as moldy core, a fungal disease, of the seed cavity because of an open calyx, often due to Alternaria ssp.
This new cultivar produces a moderately vigorous, spreading tree which comes into bearing early. This tree is productive with fruit maturity one week before xe2x80x98Deliciousxe2x80x99 (unpatented). Fruits averaging 80 mm in diameter weigh an average of about 201 g. The fruit is 90% medium red, up to 76 mm (3 inches) in diameter when well thinned, with very good dessert quality and excellent storage ability; the fruit typically exhibits the following characteristics: soluble solids=12.8%; penetrometer pressure=8.3 kg; titratable acidity=0.432 g malic acid equivalent/100 ml. The fruit is delicately spicy with a full flavor that combines sweetness and subacidity; very good, improves to best after 1 or more months in storage. After observation, the selection was asexually propagated by grafting to various rootstocks in Lafayette, Ind. and New Salisbury, Ind., and the grafted material has retained the described characteristics after propagation. The tree was selected when grown on its own roots and subsequently grown as grafted plants and tested in Indiana with seedling rootstock, Malling 7 (M.7) rootstock, and Malling-Merton 111(MM.111) rootstock. The new cultivar is precocious when grafted. The tree is considered diploid based on breeding behavior.